Sheet metal bending brake

ABSTRACT

A sheet metal bending brake having spaced upper and lower support arms with a base member fixed to the lower arms and a clamping member pivoted to the upper arms and aligned with the base member. The clamping member is normally held in a released position by biasing springs and is pivoted to a locked position by a slidable locking member guided on the clamping member and having cams engaging antifriction lugs extending below the upper support arms.

United States Patent Eugene H. Van Cleave Redford, Mich.

Jan. 27, 1969 July 13, 1971 Van Mark Products Corporation Detroit, Mich.

inventor Appl. No. Filed Patented Assignee SHEET METAL BENDING BRAKE 8 Claims, 2 Drawing Figs.

11.8. CI 72/319 Int. Cl 821d 11/04 Field of Search 72/310, 316, 318. 319, 320, 321, 322

References Cited UNITED STATES PATENTS 9/ 1964 Rauen et al 12/1969 Bamack 12/1964 Marsh Primary Examiner-rCharles W. Lanham Assistant Examiner-Michael J. Keenan Attorney-Settle, Batchelder and O1tman ABSTRACT: A sheet metal bending brake having spaced upper and lower support arms with a base member fixed to the lower arms and a clamping member pivoted to the upper arms and aligned with the base member. The clamping member is normally held in a released position by biasing springs and is pivoted to a locked position by a slidable locking member guided on the clamping member and having cams engaging antifriction lugs extending below the upper support arms.

SHEET METAL BENDING BRAKE BACKGROUND OF THE INVENTION The present invention relates generally to sheet metal bending brakes and more particularly to an improved locking and clamping mechanism for such brakes.

conventionally, sheet metal bending brakes include a pair of relatively movable members which are capable of clamping a piece of sheet metal therebetween. One of the members has a third member pivotally secured thereto which is utilized as the bending member with the edge of the remaining member defining the bending edge for the sheet metal.

Recently it has been proposed to fixedly secure one of the relatively movable members to lower arms of C-shaped supports with the other of the relatively movable members being moved vertically by a slidable locking member having lugs which engage the upper arms of the support. Such devices are disclosed in Marsh US. Pat. No. 3,161,223 and Rauen et al. No. 3,147,791.

SUMMARY OF THE INVENTION The present invention constitutes an improvement over the prior art devices disclosed in the above-mentioned patent. More specifically, the present invention contemplates pivotally supporting the upper or clamping member on the upper arms of the C-shaped supports and guiding the locking member along a specifically defined channel or guideway formed on the clamping member. The upper arms are provided with antifriction projections which extend below the lower surface thereof and are engageable with cam members carried by the locking member so that the entire device can be readily adjusted for any possible variations in dimensions as well as utilizing the device with sheet metal of varying thickness.

Thus, the primary object of the present invention is to provide a sheet metal bending brake having an improved locking mechanism for clamping a piece of sheet metal therein.

Another object is to provide an improved sheet metal bending brake having a clamping member which is pivotally supported on support arms and which has improved engaging surfaces between the fixed supports and the locking member for the device.

A further object of the invention is to provide an improved sheet metal bending brake having a removable cover on the bending edge thereof so as to be readily replaced to maintain the integrity of the bending edge at all times.

Other objects of this invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

AS SHOWN ON THE DRAWINGS F IG. 1 of the drawings discloses a perspective view of the bending brake constructed in accordance with the present invention; and I FIG. 2 is a vertical sectional view taken generally along lines 2-2 of FIG. 1.

DETAILED DESCRIPTION Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is only for the purpose of description.

FIG. 1 of the drawings shows a sheet metal bending brake l constructed in accordance with the present invention. The bending brake includes a support 12 supporting clamping members 14 and 16.

The support 12 comprises a pair of U-shaped members 20 having upper and lower arms 22 and 24 extending horizontally with the support members held in fixed spaced relation to each other by members 26 and 28. The opposite ends of the members 26 and 28 may have carrying handles 29 secured thereto. While the members 26 and 28 are in the form of hollow rectangular elements and only two supports 20 are shown, it is readily apparent that any number of supports 20 may be utilized and any specific configuration of members 26 and 28 may be utilized. The lower arms 24 of the respective C-shaped or U-shaped members 20 may be fixedly secured to the support elements 26 and 28 in any manner, such as by bolts (not shown).

The lower arms of the supports 20 have the lower or first clamping member 14 fixedly secured thereto. As more clearly shown in FIG. 2, the upper front edge of the lower arms 24 define acute angle surfaces which cooperate with acute angle surfaces defined on the angle member 14 and are again fixedly secured thereto in any manner, as by bolts (not shown).

The horizontal leg 32 of the lower clamping member or base plate supports a further plate 34, for a purpose which will become apparent hereinafter.

The upper relatively movable member or gripping plate 16 is mounted and guided for movement in accordance with the primary aspect of the present invention. Thus, the gripping plate or clamping member 16 includes a generally angled iron portion having a vertically extending leg 40 and a horizontally extending leg 42.

The horizontally extending leg 42 has an upwardly and outwardly inclined continuous projection 44 which terminates in an edge. The portion 44 also has spaced recesses 46 defined thereon which have a horizontal extent sufiicient to receive the upper arms 22 as in more clearly shown in FIG. 1. The edge defined on the inclined portion 44 has a continuous bulbous portion 48, except for the recessed areas 46, which has an opening defined therein. Also, the upper arms 22 likewise have enlarged portions 52 which have aligned openings therein. A hinge pin 54 extends through the openings defined in the edge 48 of the pivoted clamping member 16 and the enlarged portions 52 defining therein a pivot support. Thus, it can be seen that the specific arrangement of connecting the clamping member to the support allows for pivotal movement of the front edge of the clamping member towards and away from the fixed base of platen 14.

As is conventional in bending brakes of this type, the clamping member 14 has a bending edge defined thereon and, in the embodiment disclosed in the drawings, this bending edge is defined by a triangular'shaped projection 60 extending from the angle iron forming the main body of the clamping member.

According to the primary aspect of the present invention, ,the clamping member 16 is moved between first and second positions by a locking member 62 which is slidably supported in a guideway 64 defined along the upper surface of the angle member defined by legs 40 and 42. The locking member 62 is moved horizontally between first and second positions by a lever 66 pivoted at its lower end on a pin 68 carried by a bifurcated bracket 70 which in turn may be pivoted on a pin 72 fixedly carried on the lower surface of the lower clamping member 14.

v The means for moving the locking member 62 between locking and released positions further includes a pivotal connection between an intermediate portion of the lever 66 and the locking member 62. This is more clearly illustrated in FIG. 1 and includes a bifurcated bracket 74 fixedly secured to one end of the member 62 and pivotally connected to the lever 66 by pin 76. The locking member 62 supports spaced camming members which have inclined camming surfaces 82 on the upper edge thereof.

According to a further aspect of the present invention, the camming surfaces 82 cooperate with antifriction devices carried by the upper arms 22. Thus, as more clearly shown in FIG. 2, the upper arms 22 each have a threaded opening which threadedly receives a member 92 having an upper threaded portion and a tower antifriction portion 94 The an tifriction portion or plastic pro ection extends below the lower surface of the respective arms 22 and engages the upper surface 82 of the camming members 80.

The clamping member 16 1S pivotally biased to a released position by biasing means specifically configured and located in accordance with a further aspect of the present invention The biasing means includes U-shaped spring clips having a base portion 100 with a pair of legs 102 extending from opposite ends of the base 100. As more clearly shown in FIG 2. the base portion extends horizontally below the lower surface of the upper arms 22 and the respective legs 102 extend on opposite sides of the arms 22. The spring legs 102 overlie the hinge pin 54 and the projection 46 or 52 and then extend into the recesses 46 defined adjacent each of the arms 22 and the free ends of the respective arms extend below and engage the lower surface of the projection or extension 44. Thus, it will be seen that the biasing means or spring clips will normally maintain the clamping members 16 in an upper or released position wherein the bending edge 60 is spaced from the surface defined on the plate 3 3. Of course, pivotal movement of the lever 66 towards the main body of the clamping sheet metal bending brake will cause a relative movement of the camming surface 82 against the lower ends of the projection and particularly the antifriction portions 94 to move the clamping member from the released position defined by the biasing means to the clamping position shown in FIG. 2.

As is conventional in sheet metal bending brakes of this type, the bending is done by a bending member 120 which is in the form of a member with two legs and having integral based projections 122 at the one end of one ofthe legs which cooperate with projections 124 defined on the base member 14. The projections 122 and 124 have openings which receive a hinge pin 126 so that the entire bending member 120 is pivoted with respect to the member 16. In the illustrated embodiment, the bending member further includes a projection 128 defined on the forward surface of the vertically extending leg which defines a ledge against which the bending member 130 rests and is held in substantially fixed position by spring clips 132. Thus the upper edge 134 of the bending member 130 engages sheet metal which is disposed between the clamping members 14 and 16 and bends the sheet metal about the bending edge 60.

According to a further aspect of the present invention, the bending edge defined by projection 60 also has a removable cover plate 140 clipped thereto which can readily be removed and replaced. This particular feature is of considerable advantage to increasing the life of the entire bending device and particularly the upper clamping member. In many phases of operation utilizing the sheet metal the sheet metal bending brake constructed in accordance with the present invention, it is necessary for the worker to cut the metal, such as aluminum, to a specific width. Thus, it has become conventional practice to merely clamp the sheet metal between the two clamping members 14 and 16 and to run a sharp object along the bending edge defined by the projection 60. Thereafter, the bending member 120 is pivoted on the clamping member 14 and the metal is snapped along the basic cut made along the bending edge. In operations of this type, it is impossible to maintain the integrity of the entirebending edge and after short periods of use the bending edge becomes knicked and uneven. Thus, by providing a removable cover 140 of a substantially hard material, such as stainless steel, the life of the upper clamping member is substantially increased. Furthermore, with a removable cover member 140 it is a very simple matter to merely remove a damaged cover member and replace it with a new one so as to provide a net. tending edge for the sheet metal bending brake.

I claim:

1. A brake for bending sheet metal, comprising means defining upper and lower vertically spaced support arms, a first member fixed on said lower arms. a clamping member having one edge pivotally supported on a pivot support on said upper arms for movement toward and away from said first member, means defining a guideway on said clamping member, a locking member slidable in said guideway, means for moving said locking member between first and second positions, cam means on said locking member cooperating with said upper arms whereby sliding movement of said locking member in said guideway to the first position will pivot said clamping member on said upper arms to move said clamping member toward said first member to clamp a workpiece therebetween; and means cooperatively connected between said upper support arms and said clamping member at said pivot support to continuously urge said clamping member towards said locking member.

2. A brake as defined in claim 1, including the further improvement of means defining removable antifriction devices extending below said upper arms and engageable with said cam means.

3. A brake as defined in claim 1, and wherein said upper arms are horizontally spaced, the further improvement of means defining spaced recesses on said one edge with each recess receiving a portion of one of said arms, means defining a continuous opening along said edge and in said portions of said arms, and a hinge pin extending through said opening for pivoting said clamping member on said upper arms.

4. A brake as defined in claim 3, including the further improvement of a U-shaped spring member disposed between each upper arm and said clamping member, said spring members each having a base portion disposed below and spanning the horizontal portion of one of said upper arms and legs extending on opposite sides of the arm and overlying said hinge pin, said legs extending into said recesses and having free ends engageable with the lower surface of said clamping member for maintaining said clamping member spaced from said first member when said locking member is moved from the first portion.

5. In a brake for bending metal sheets including a baseplate, a plurality of arms overlying and spaced above said baseplate, a gripping plate adapted to clamp the metal sheets on said baseplate, the improvement of means defining recesses on one edge of said gripping plate with each recess receiving one of said arms, a hinge pin extending through said gripping plate along said edge and through portions of said arms received in said recesses for pivotally supporting said gripping plate, biasing means normally maintaining said gripping plate in the release position and means for pivoting said gripping plate from the release position to a clamping position to clamp the sheet metal between said plates; said last means including a locking member slidably guided along the upper surface of said gripping plate and parallel to said edge, a nonmetallic projection extending below each of said arms and cam means on the upper surface of said locking member, each said cam means aligned and engageable with one of said projections whereby sliding movement of said locking member between first and second position will pivot said gripping plate between release and clamping positions; and said biasing means operably connected between said arms and said gripping plate for continuously urging said gripping plate towards said locking member in either released or clamped position.

6. A brake as defined in claim 5, including the further improvement of said projections each comprising a member threaded in an opening in each of said arms and having a nonmetallic portion extending below the lower surfaces of said arms.

7. A brake as defined in claim 5, including the further improvement of said biasing means comprising a spring clip for each of said arms, said spring clips each comprising a base portion and spaced legs extending from opposite ends of said base portion, said base portions engaging lower surfaces of respective arms and having said legs extending on opposite sides of one of said arms and overlying said hinge pin, said legs having portions received in said recesses and free ends in extended engagement with the lower surface of said gripping plate to said release position.

8. A brake as defined in claim 5, and wherein said gripping plate includes a bending edge spaced from said one edge, the further improvement of a removable cover enclosing said bending edge. 

1. A brake for bending sheet metal, comprising means defining upper and lower vertically spaced support arms, a first member fixed on said lower arms, a clamping member having one edge pivotally supported on a pivot support on said upper arms for movement toward and away from said first member, means defining a guideway on said clamping member, a locking member slidable in said guideway, means for moving said locking member between first and second positions, cam means on said locking member cooperating with said upper arms whereby sliding movement of said locking member in said guideway to the first position will pivot said clamping member on said upper arms to move said clamping member toward said first member to clamp a workpiece therebetween; and means cooperatively connected between said upper support arms and said clamping member at said pivot support to continuously urge said clamping member towards said locking member.
 2. A brake as defined in claim 1, including the further improvement of means defining removable antifriction devices extending below said upper arms and engageable with said cam means.
 3. A brake as defined in claim 1, and wherein said upper arms are horizontally spaced, the further improvement of means defining spaced recesses on said one edge with each recess receiving a portion of one of said arms, means defining a continuous opening along said edge and in said portions of said arms, and a hinge pin extending through said opening for pivoting said clamping member on said upper arms.
 4. A brake as defined in claim 3, including the further improvement of a U-shaped spring member disposed between each upper arm and said clamping member, said spring members each having a base portion disposed below and spanning the horizontal portion of one of said upper arms and legs extending on opposite sides of the arm and overlying said hinge pin, said legs extending into said recesses and having free ends engageable with the lower surface of said clamping member for maintaining said clamping member spaced from said first member when said locking member is moved from the first portion.
 5. In a brake for bending metal sheets including a baseplate, a plurality of arms overlying and spaced above said baseplate, a gripping plate adapted to clamp the metal sheets on said baseplate, the improvement of means defining recesses on one edge of said gripping plate with each recess receiving one of said arms, a hinge pin extending through said gripping plate along said edge and through portions of said arms received in said recesses for pivotally supporting said gripping plate, biasing means normally maintaining said gripping plate in the release position and means for pivoting said gripping plate from the release position to a clamping position to clamp the sheet metal between said plates; said last means including a locking member slidably guided along the upper surface of said gripping plate and parallel to said edge, a nonmetallic projection extending below each of said arms and cam means on the upper surface of said locking member, each said cam means aligned and engageable with one of said projections whereby sliding movement of said locking member between first and second position will pivot said gripping plate between release and clamping positions; and said biasing means operably connected between said arms and said grippIng plate for continuously urging said gripping plate towards said locking member in either released or clamped position.
 6. A brake as defined in claim 5, including the further improvement of said projections each comprising a member threaded in an opening in each of said arms and having a nonmetallic portion extending below the lower surfaces of said arms.
 7. A brake as defined in claim 5, including the further improvement of said biasing means comprising a spring clip for each of said arms, said spring clips each comprising a base portion and spaced legs extending from opposite ends of said base portion, said base portions engaging lower surfaces of respective arms and having said legs extending on opposite sides of one of said arms and overlying said hinge pin, said legs having portions received in said recesses and free ends in extended engagement with the lower surface of said gripping plate to said release position.
 8. A brake as defined in claim 5, and wherein said gripping plate includes a bending edge spaced from said one edge, the further improvement of a removable cover enclosing said bending edge. 